U.S. patent application number 17/126980 was filed with the patent office on 2021-04-08 for systems, methods and devices for progressively softening multi-compositional intravascular tissue.
The applicant listed for this patent is Cardiovascular Systems, Inc.. Invention is credited to Victor L. Schoenle.
Application Number | 20210100570 17/126980 |
Document ID | / |
Family ID | 1000005290214 |
Filed Date | 2021-04-08 |
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United States Patent
Application |
20210100570 |
Kind Code |
A1 |
Schoenle; Victor L. |
April 8, 2021 |
SYSTEMS, METHODS AND DEVICES FOR PROGRESSIVELY SOFTENING
MULTI-COMPOSITIONAL INTRAVASCULAR TISSUE
Abstract
Various embodiments of the systems, methods and devices are
provided comprising angioplasty to break up calcification or other
tissue in occlusive areas within a blood vessel. The various
embodiments disclosed comprise pressure pulse periods designed to
break up calcified occlusive material through a cyclically
stretching of the vessel walls without damaging the vessel wall
tissue.
Inventors: |
Schoenle; Victor L.;
(Greenfield, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cardiovascular Systems, Inc. |
New Brighton |
MN |
US |
|
|
Family ID: |
1000005290214 |
Appl. No.: |
17/126980 |
Filed: |
December 18, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15859961 |
Jan 2, 2018 |
10898214 |
|
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17126980 |
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62441796 |
Jan 3, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 25/10184 20131105;
A61B 2017/22001 20130101; A61B 2017/22062 20130101; A61M 25/104
20130101; A61B 2017/00154 20130101; A61B 17/22012 20130101; A61M
25/10182 20131105 |
International
Class: |
A61B 17/22 20060101
A61B017/22; A61M 25/10 20060101 A61M025/10 |
Claims
1. A system for treating a blood vessel, comprising: an inflatable
balloon operatively connected to a catheter; a fluid reservoir in
operative fluid communication with the inflatable balloon; a
pressure controller in operative communication with the fluid
reservoir and adapted to deliver fluid from the fluid reservoir
with a plurality of pressure pulse periods, each pressure pulse
period comprising at least one balloon inflation comprising at
least one pressure magnitude, the pressure controller further
adapted to provide a relaxation period between successive pressure
pulse periods, each relaxation period comprising a balloon pressure
that is greater than zero; and a processor in operative
communication with the pressure controller, the processor
comprising programmed instructions that, when executed, results in
programmed execution of the plurality of pulse periods and the
relaxation period between successive pulse periods.
2. The system of claim 1, wherein the programmed instructions
further comprise at least one of the predetermined variables in the
group consisting of: initial pressure magnitude, maximum pressure
magnitude, final pressure magnitude, time of pressure application,
time of relaxation period, pressure of relaxation period, and
velocity of pressure application.
3. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the at least one pressure magnitude
increases within each successive pressure pulse period in the
plurality of pulse periods over time.
4. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the plurality of pulse periods each comprise
a predetermined initial minimum pressure magnitude.
5. The system of claim 4, wherein the programmed instructions are
adapted to ensure that the predetermined initial minimum pressure
magnitudes are not the same for any of the pressure pulse periods
in the plurality of pressure pulse periods.
6. The system of claim 4, wherein the programmed instructions are
adapted to ensure the predetermined initial minimum pressure
magnitudes increase across the plurality of pulse periods over
time.
7. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the plurality of pulse periods each comprise
a predetermined maximum pressure magnitude.
8. The system of claim 7, wherein the programmed instructions are
adapted to ensure that the predetermined maximum pressure
magnitudes are not the same for any of the pressure pulse periods
in the plurality of pressure pulse periods.
9. The system of claim 7, wherein the programmed instructions are
adapted to ensure that the predetermined maximum pressure
magnitudes increase across the plurality of pulse periods over
time.
10. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the pressure pulse period for each
successive pressure pulse period within the plurality of pressure
pulse periods comprises a constant time period.
11. The system of claim 1, wherein the programmed instructions are
adapted to ensure that each successive pressure pulse period within
the plurality of pressure pulse periods comprise unequal time
periods.
12. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the each successive pressure pulse period
within the plurality of pressure pulse periods increases in
time.
13. The system of claim 1, wherein wherein the programmed
instructions are adapted to ensure that the relaxation period
between successive pressure pulse periods comprises a time period
that is constant.
14. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the decompression period between successive
pressure pulse periods comprises a time period that is
variable.
15. The system of claim 1, wherein the programmed instructions are
adapted to ensure that the decompression period between successive
pressure pulse periods comprises a time period that increases.
16. The system of claim 1, wherein each of the at least one balloon
inflations comprise a predetermined waveform type.
17. The system of claim 16, wherein the predetermined waveform type
does not change within each pressure pulse period or across the
series of pressure pulse periods.
18. The system of claim 16, wherein the at least one waveform type
does change within at least one of the pressure pulse periods
within the series of pressure pulse periods.
19. The system of claim 1, wherein the wherein the programmed
instructions are adapted to ensure that the pressure velocity at
the initiation of each of the pressure pulse periods within the
series of pressure pulse periods is constant and does not vary
between pressure pulse periods.
20. The system of claim 1, wherein the wherein the programmed
instructions are adapted to ensure that the pressure velocity at
the initiation of each of the pressure pulse periods within the
series of pressure pulse periods is not the same for all of the
pressure pulse periods.
21. The system of claim 1, wherein the wherein the programmed
instructions are adapted to ensure that the pressure velocity at
the initiation of each of the pressure pulse periods within the
series of pressure pulse periods increases with each successive
pressure pulse period.
22. A method for treating a blood vessel with an inflatable balloon
catheter, comprising: providing the inflatable balloon catheter in
operative and fluid communication with a pressure controller;
inserting the inflatable balloon catheter within the blood vessel
to a location of interest; using the pressure controller to execute
a series of inflations, with relaxation periods between each
inflation, wherein each relaxation period comprises a balloon
pressure magnitude greater than zero.
23. The method of claim 22, further comprising ensuring that each
inflation in the series of inflations comprises successively
greater pressure magnitudes within the balloon.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Utility
application Ser. No. 15/859,961, filed Jan. 2, 2018 and entitled
SYSTEMS, METHODS AND DEVICES FOR PROGRESSIVELY SOFTENING
MULTI-COMPOSITIONAL INTRAVASCULAR TISSUE and also claims the
benefit of U.S. Provisional Application No. 62/441,796, filed Jan.
3, 2017 and entitled SYSTEMS, METHODS AND DEVICES FOR STRESS
SOFTENING MULTI-COMPOSITIONAL INTRAVASCULAR TISSUE, the entire
contents of which are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] The invention relates to systems, devices and methods for
breaking up calcified lesions in an anatomical conduit. More
specifically, specific incremental pressure increases are provided
to a balloon within a calcified conduit, e.g., a blood vessel, to
break the calcified material while not damaging the tissue of the
vessel wall.
Description of the Related Art
[0004] A variety of techniques and instruments have been developed
for use in the removal or repair of tissue in arteries and similar
body passageways. A frequent objective of such techniques and
instruments is the removal of atherosclerotic plaque in a patient's
arteries. Atherosclerosis is characterized by the buildup of fatty
deposits (atheromas) in the intimal layer (i.e., under the
endothelium) of a patient's blood vessels. Very often over time
what initially is deposited as relatively soft, cholesterol-rich
atheromatous material hardens into a calcified atherosclerotic
plaque. Such atheromas restrict the flow of blood, and therefore
often are referred to as stenotic lesions or stenoses, the blocking
material being referred to as stenotic material. If left untreated,
such stenoses can cause angina, hypertension, myocardial
infarction, strokes and the like.
[0005] Angioplasty, or balloon angioplasty, is an endovascular
procedure to treat by widening narrowed or obstructed arteries or
veins, typically to treat arterial atherosclerosis. A collapsed
balloon is typically passed through a pre-positioned catheter and
over a guide wire into the narrowed occlusion and then inflated to
a fixed size. The balloon forces expansion of the occlusion within
the vessel and the surrounding muscular wall until the occlusion
yields from the radial force applied by the expanding balloon,
opening up the blood vessel with a lumen inner diameter that is
similar to the native vessel in the occlusion area and, thereby,
improving blood flow.
[0006] The angioplasty procedure does present some risks and
complications, including but not limited to: arterial rupture or
other damage to the vessel wall tissue from over-inflation of the
balloon catheter, the use of an inappropriately large or stiff
balloon, or the presence of a calcified target vessel; and/or
hematoma or pseudoaneurysm formation at the access site. As
described above, the primary problem with known angioplasty systems
and methods is that the occlusion yields over a relatively short
time period at high stress and strain rate, often resulting in
damage or dissection of the conduit, e.g., blood vessel, wall
tissue.
[0007] Currently, the best way to deal with the high stress strain
of blood vessel, e.g., artery, wall tissue adjacent to calcified
occlusions is to use an atherectomy system marketed by
Cardiovascular Systems, Inc., ("CSI") assignee of the instant
application. This system comprises an abrasive crown mounted on the
drive shaft, wherein the abrasive crown is "eccentric," i.e., with
a center of mass located radially away from the drive shaft's axis
of rotation. This eccentric (or non-concentric) crown sands and
removes calcium internal to the intimal layer of the subject vessel
wall in combination with impact energy from the orbiting rotational
eccentric crown which works to break and/or soften the embedded
calcified plaque.
[0008] The CSI atherectomy system and method typically increases
the compliance of the calcified occlusion. This is confirmed by
balloon inflations requiring lower inflation pressures post
atherectomy procedure than non-atherectomy cases. However, the CSI
atherectomy system and method may still the use of an adjunctive
dilatation balloon to improve lumen diameter gain at the occlusion
when there is calcium present within the intimal wall, i.e., not
located within the vessel lumen.
[0009] Moreover, we provide disclosure of the following patents and
applications, each of which are assigned to Cardiovascular Systems,
Inc., and incorporated herein in their entirety, each of which may
comprise systems, methods and/or devices that may be used with
various embodiments of the presently disclosed subject matter:
[0010] U.S. Pat. No. 6,295,712, "ROTATIONAL ATHERECTOMY
DEVICE";
[0011] U.S. Pat. No. 6,494,890, "ECCENTRIC ROTATIONAL ATHERECTOMY
DEVICE";
[0012] U.S. Pat. No. 6,132,444, "ECCENTRIC DRIVE SHAFT FOR
ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE";
[0013] U.S. Pat. No. 6,638,288, "ECCENTRIC DRIVE SHAFT FOR
ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE";
[0014] U.S. Pat. No. 5,314,438, "ABRASIVE DRIVE SHAFT DEVICE FOR
ROTATIONAL ATHERECTOMY";
[0015] U.S. Pat. No. 6,217,595, "ROTATIONAL ATHERECTOMY
DEVICE";
[0016] U.S. Pat. No. 5,554,163, "ATHERECTOMY DEVICE";
[0017] U.S. Pat. No. 7,507,245, "ROTATIONAL ANGIOPLASTY DEVICE WITH
ABRASIVE CROWN";
[0018] U.S. Pat. No. 6,129,734, "ROTATIONAL ATHERECTOMY DEVICE WITH
RADIALLY EXPANDABLE PRIME MOVER COUPLING";
[0019] U.S. patent application Ser. No. 11/761,128, "ECCENTRIC
ABRADING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY DEVICES";
[0020] U.S. patent application Ser. No. 11/767,725, "SYSTEM,
APPARATUS AND METHOD FOR OPENING AN OCCLUDED LESION";
[0021] U.S. patent application Ser. No. 12/130,083, "ECCENTRIC
ABRADING ELEMENT FOR HIGH-SPEED ROTATIONAL ATHERECTOMY
DEVICES";
[0022] U.S. patent application Ser. No. 12/363,914, "MULTI-MATERIAL
ABRADING HEAD FOR ATHERECTOMY DEVICES HAVING LATERALLY DISPLACED
CENTER OF MASS";
[0023] U.S. patent application Ser. No. 12/578,222, "ROTATIONAL
ATHERECTOMY DEVICE WITH PRE-CURVED DRIVE SHAFT";
[0024] U.S. patent application Ser. No. 12/130,024, "ECCENTRIC
ABRADING AND CUTTING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY
DEVICES";
[0025] U.S. patent application Ser. No. 12/580,590, "ECCENTRIC
ABRADING AND CUTTING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY
DEVICES";
[0026] U.S. patent application Ser. No. 29/298,320, "ROTATIONAL
ATHERECTOMY ABRASIVE CROWN";
[0027] U.S. patent application Ser. No. 29/297,122, "ROTATIONAL
ATHERECTOMY ABRASIVE CROWN";
[0028] U.S. patent application Ser. No. 12/466,130, "BIDIRECTIONAL
EXPANDABLE HEAD FOR ROTATIONAL ATHERECTOMY DEVICE";
[0029] U.S. patent application Ser. No. 12/388,703, "ROTATIONAL
ATHERECTOMY SEGMENTED ABRADING HEAD AND METHOD TO IMPROVE ABRADING
EFFICIENCY";
[0030] U.S. patent application Ser. No. 13/624,313, "ROTATIONAL
ATHERECTOMY DEVICE WITH ELECTRIC MOTOR";
[0031] U.S. patent application Ser. No. 14/315,774, "DEVICES,
SYSTEMS AND METHODS FOR LOCALLY MEASURING BIOLOGICAL CONDUIT AND/OR
LESION COMPLIANCE, OPPOSITION FORCE AND INNER DIAMETER OF A
BIOLOGICAL CONDUIT"; and
[0032] U.S. patent application Ser. No. 14/801,269, "METHODS,
DEVICES AND SYSTEMS FOR SENSING, MEASURING AND/OR CHARACTERIZING
VESSEL AND/OR LESION COMPLIANCE AND/OR ELASTANCE CHANGES DURING
VASCULAR PROCEDURES".
[0033] Various embodiments of the present invention address the
issues, among others, discussed above.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0034] FIG. 1 is a graphic illustration of a typical stress strain
curve of a single balloon inflation to the point where the artery
wall tissue is damaged.
[0035] FIG. 2 is a graphic indicating that arteries with higher
collagen content will be softened to a greater degree than arteries
with lower collagen content.
[0036] FIG. 3 is a graphic illustrating that different arteries
have different collagen to elastin ratios.
[0037] FIG. 4 is a pressure plot obtained using one embodiment of
the present invention.
[0038] FIG. 5 is a graphic illustration of balloon diameter change
in conjunction with the pressures employed in the embodiment of the
present invention giving rise to the pressure plot of FIG. 4.
[0039] FIG. 6 illustrates a schematic view of one embodiment of the
present invention.
[0040] FIG. 7 illustrates a schematic view of one embodiment of the
present invention.
[0041] FIG. 8A illustrates a pressure plot for an embodiment of the
present invention.
[0042] FIG. 8B illustrates a diameter plot for the embodiment of
FIG. 8A.
[0043] FIG. 8C illustrates a pressure plot for another embodiment
of the present invention.
[0044] FIG. 8D illustrates a diameter plot for the embodiment of
FIG. 8C.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Various embodiments of the present invention are illustrated
in the Figures. Thus, FIG. 1 is a graphic illustration comprising a
reference line 10 illustrating the typical stress strain curve of a
single balloon inflation procedure to the point where the artery
wall is damaged. The remaining lines, and dots, illustrate how a
pulsatile inflation/cyclically stretched pressure pulse period
serially applied as described herein lowers the applied stress for
a given strain on the artery wall and/or may be strained further at
similar safe stress levels.
[0046] FIG. 2 is a graphic indicating that arteries with higher
collagen content will be softened to a greater degree than arteries
with lower collagen content. FIG. 3 is a graphic illustrating that
different arteries have different collagen to elastin ratios.
[0047] FIG. 4 is a pressure plot obtained using one embodiment of
the present invention in a cadaver study. The method creates a
successive series of pressure pulse periods with 40 steps per
atmosphere wherein the velocity (strain rate) was set to a unit
less number of 15. The steps may be modified to any number, e.g., 1
to 99 steps and the velocity may also be modified to any number,
e.g., from 1 to 99.
[0048] FIG. 5 is a graphic illustration of balloon diameter change
in conjunction with the pressures employed in the embodiment of the
present invention giving rise to the pressure plot of FIG. 4. The
balloon diameter changes are driven by the material properties and
will vary between manufacturers and models of the various known
balloons.
[0049] Thus, certain embodiments of the present invention comprise
a plurality of pressure pulse periods, with relaxation periods
therebetween, delivered via a balloon placed within an occlusion
within a biological conduit, e.g., a blood vessel such as an
artery. Each pressure pulse period comprises a beginning timepoint
with an initial minimum pressure magnitude (IMPM) and an ending
timepoint with a final maximum pressure magnitude (FMPM). The
pressure pulse periods may increase, or vary, pressure magnitude
within each pressure pulse period and/or may comprise a single
magnitude pressure magnitude within each pressure pulse period. In
addition, the time interval for each pressure pulse period may
successively increase from an initial pressure pulse period time
interval to a final pressure pulse period time interval, as shown
in FIG. 5. Alternatively, the time intervals T for the pressure
pulse period applications may be substantially equivalent in
certain embodiments. Further, the pressure pulse periods may
increase in magnitude from an initial pressure pulse period 102 to
a final pressure pulse period 104 as is best illustrated in FIG. 4.
In addition, the pressure magnitude within an individual pressure
pulse period may be constant or may increase, or otherwise be
variable. For example, each pressure pulse period may comprise a
successively increasing plurality of pressure magnitudes between
the initial minimum pressure magnitude (IMPM) and the final maximum
pressure magnitude (FMPM). An example of increasing pressure
magnitude within individual pressure pulse periods is shown in
FIGS. 4 and 5, with 5 illustrating the related radial expansion of
the balloon as referenced by the y-axis. As shown in FIG. 4, each
pressure pulse period may further comprise an initiation pressure
magnitude (IPM) adapted to initiate a successive pressure pulse
period, with the initiation pressure magnitude (IPM) being greater
than zero and less than the final maximum pressure magnitude of the
immediately preceding pressure pulse period in the series of
pressure pulse periods. In such examples, the final maximum
pressure magnitude increases across the series of pressure pulse
periods (e.g., with the final maximum pressure magnitude of at
least one successive pulse period being greater than the final
maximum pressure magnitude (FMPM) of each preceding pressure pulse
period). In addition, the initial minimum pressure magnitude (IMPM)
of at least one successive pulse period may be greater than the
initial minimum pressure magnitude of each preceding pressure pulse
period, as shown in FIG. 4.
[0050] Accordingly, and with reference to FIGS. 4, 5 and 8A-8D, a
method according to certain embodiments of the present invention
comprise a series 100 of pressure pulse periods P applied to the
internal walls of a blood vessel over a period of time, each
pressure pulse period P comprising a time T that may be constant or
may vary, e.g., increase with each successive pressure pulse period
P within the series of pressure pulse periods 100. Each pressure
pulse period P may comprise balloon inflation(s) comprising at
least one pressure wave form, a pressure magnitude or magnitudes
within each individual pressure wave form and/or across the
pressure pulse period comprising one or more pressure wave forms.
The pressure magnitude is represented in FIG. 4 by the y-axes, with
time on the x-axis. The pressure magnitude for each pressure wave
form may be constant within the wave form or may vary, e.g., may
increase with time. Alternatively, or in combination with the
pressure magnitude, the balloon's radial expansion may be a further
element of the pressure pulse period(s) as illustrated by the
y-axis in FIG. 5, as defined by an initial minimum diameter (IMD)
and a final maximum diameter (FMD) for the balloon during each
pressure pulse period. Further, each pressure wave form may
comprise a time of pressuring 102 that may be constant or that may
vary across the pressure wave forms of the series of pressure pulse
periods. Moreover, a decompression, or relaxation, period between
each successive or adjacent pressure wave forms D is provided to
allow the vessel material time to relax and realign. As illustrated
in FIG. 4, a decompression, or relaxation, period between
successive pressure pulse periods may comprise at least one
pressure magnitude within the balloon that is greater than zero.
The length in time of the decompression/relaxation periods may be
equal through the series of pressure pulse periods or may be
variable. Finally, with particular reference to FIGS. 8A-8D, the
velocity of the pressure increase, i.e., balloon inflation, at the
beginning of an individual pressure pulse period, and the velocity
of the pressure decrease, i.e., balloon deflation, at the end of an
individual pressure pulse period are significant elements of the
series of pressure pulse periods.
[0051] It will be understood that the series of pressure pulse
periods 100, and all elements and variables comprising the series
of pressure pulse periods 100 may be predetermined and executed
using a controller comprising a processor capable of executing
programmed instructions that, when executed, result in a balloon
expansion regimen that follows the series of pressure pulse periods
100.
[0052] Examples of pressure pulse period series 100 are provided in
FIGS. 4, 5 and 8A-8D. FIGS. 8A-8D illustrate some exemplary wave
forms that may be used to achieve the intended results of the
present invention. However, pulses, velocities and waveforms used
in various embodiments of the present invention may vary, as shown
in FIGS. 8A-8D. For example, wave forms may be non-variable in
shape, for example a repeating constant pressure such as a sine
wave of constant peak magnitude and period (time), or may be
variable, i.e., with varying pressure and/or period. In addition,
the pressure waveform types may be the same, e.g., all sine waves,
within a particular pressure pulse period P, or the waveforms may
vary within a pressure pulse period P, e.g., sine waves alternating
with square waves and/or triangle waves or saw tooth waves as the
skilled artisan will readily recognize. Similarly, the waveform
types may be constant, or may vary across the series of pressure
pulse periods 100 so that one pressure pulse period P in the series
of pressure pulse periods 100 employs square waves and a second
pressure pulse period P in the series of pressure pulse periods 100
employs saw tooth waves. The skilled artisan will recognize
equivalents of these parameters, all of which are within the scope
of the present invention.
[0053] Thus, the balloon outer diameter is systematically increased
and decreased, at specified velocities, by predetermined specific
pressure increments over predetermined time intervals. The
exemplary vessel, e.g., arterial, wall is given time to relax
between each pressure pulse period application. The cyclic nature
of longer and longer strains through each successive pressure pulse
period as shown in FIGS. 4 and 5 causes weaker short chains of
vessel wall material to disengage giving the longer and more
entangled chains of vessel wall material time to align and conform
to the strain being applied in a way that causes less overall
vessel wall material chain breakage and resulting tissue damage.
Stated differently, the pressure magnitude for each pressure pulse
period is selected so as to not deform the subject vessel wall
non-elastically. Because a preferred embodiment of the present
invention comprises an incremental increase in at least one of the
variable elements, e.g., pressure magnitude, time of pressure
application, velocity of pressure, etc., the vessel wall is allowed
to adapt to the increasing load without deformation while the
balloon breaks up calcified material.
[0054] Because the longer and more entangled vessel wall material
chains are not broken or damaged, the exemplary artery may be
strained further at safe stress levels, or the artery may be
strained to similar pressure levels as known angioplasty methods,
but with lower stress levels placed on the vessel wall over the
length of the inventive procedure, resulting in lower overall
vessel wall material chain/tissue damage.
[0055] In addition to the stress softening advantages with
reduction of tissue damage, including reduction in cell injury
responses, there is another benefit. That is, the expanded section
of conduit, e.g., a blood vessel such as an artery, that has been
stress softened will have increased compliance. This, in turn,
results in healthy normal conduit, e.g., artery, compliance with
normal blood pressure returning to the previously compromised
artery.
[0056] FIG. 6 illustrates an exemplary system for implementing the
pressure pulse periods of the various embodiments of the present
invention. Thus, a pressure controller having programmed
instructions therein and/or otherwise adapted to provide the
pressure pulse periods in a predetermined sequence as described
above is provided. The pressure controller is operatively
connected, either wired or wirelessly, to a fluid reservoir and to
a known balloon capable of fluid inflation from the reservoir
according to the instructions provided by the pressure
controller.
[0057] The functionality of the above method may be achieved using
a variety of devices including as shown in FIG. 6. Alternatively,
as in FIG. 7, the system may comprise a balloon of known
elasticity, or compliance, a device, e.g., a syringe, that is
capable of injecting a known and fixed volume of fluid to inflate
the balloon to the required pressure pulse period requirements, an
optional pressure transducer in operative communication and
connection with the inflating balloon to measure the pressure
experienced by the balloon as it inflates. There is illustrated an
exemplary linear motor that is capable of translating the plunger
of syringe to meet the pressure pulse period requirements. A
pressure transducer, when present, is in operative communication
and connection with the balloon to measure and display and/or
record the pressure data as well as the corresponding volume
data.
[0058] The system of FIG. 7 is shown in operative communication
with an external computing device comprising a memory in
communication with a processor and an input, e.g., keyboard that is
also in operative communication with the processor and a display
which is, in turn, in operative communication with the processor.
As the skilled artisan will recognize, the memory may store
programmed instructions for the series of pressure pulse periods
100 and the processor may be adapted to execute the stored
programmed instructions.
[0059] Still more alternatively, a pressure controller that
functions in a manner similar to a speaker coil in order to change
the pressure wave form at a wider/higher range of frequencies with
a wide amplitude range and with more precision may be employed to
generate the desired pressure pulse periods of the present
invention.
[0060] Various embodiments of the present invention may comprise a
combination of the incrementally pulsed balloon inflation forces
described herein with a balloon that is at least partially covered
with a wire, wherein the wires create a series of high stress
regions, or risers, that move with the balloon surface as it
expands and contracts. When the at least partially wire-covered
balloon is inflated, the wire contact pressures increase sharply
along with the artery wall becoming less compliant as it is
stretched in response to the radial expansion of the balloon. Any
rigid sections within the artery wall will be broken into smaller
pieces. As these rigid sections are broken into smaller segments,
the tissue between and surrounding the smaller rigid sections will
begin to stretch in response to the radially expanding balloon.
Without the incremental stress softening of the tissue around a
rigid section provided by the various embodiments of the present
invention, the tissue would experience high strain rates and will
likely be torn or damaged, resulting in arterial wall injury.
[0061] The methods described herein may be used on any known
percutaneous transluminal angioplasty (PTA), percutaneous
transluminal coronary angioplasty (PTCA), stent delivery system,
specialty balloons or CSI BOSS application.
[0062] The description of the invention and its applications as set
forth herein is illustrative and is not intended to limit the scope
of the invention. Features of various embodiments may be combined
with other embodiments within the contemplation of this invention.
Variations and modifications of the embodiments disclosed herein
are possible, and practical alternatives to and equivalents of the
various elements of the embodiments would be understood to those of
ordinary skill in the art upon study of this patent document. These
and other variations and modifications of the embodiments disclosed
herein may be made without departing from the scope and spirit of
the invention.
* * * * *